1. Technical Field
The present disclosure relates to a device for driving lamps, in particular HID lamps.
2. Description of the Related Art
There are known electronic devices suitable for driving lamps, in particular HID lamps. These particular lamps have a gas within the bulb, for example metal halide or mercury vapor; the lamps require a voltage even higher than 20 KV in order to be ignited for a period of a few seconds and a voltage between 80 V and 110 V in order to be maintained turned on. HID lamps work at a low frequency, from 150 to 800 Hz, in order to avoid damage due to acoustic resonance.
The device normally used to drive HID lamps is the ballast. Ballasts are formed with circuit topologies that make use of microcontrollers and rather complex configurations of power transistors. Typically, four power switches in a bridge configuration are provided, two of which work at a high frequency (80-100 KHz) to regulate the current across the lamp, whereas the other two work at a low frequency (150-400 Hz) to meet requirements of a mechanical nature of the lamp itself.
Therefore, an HID lamp requires a very particular and precise control that renders the circuit design rather complex.